Loop-taker for sewing machines



Feb. 21,1939. M. L. WATERMAN 2,143,385

LOOF-TAKER FOR SEWING MACHINES Filed Aug. 25, 1937 3 Sheets-Sheet 1 Z 4 Z? a 5 3 I- Max; L.u zier-ma 38 ,33 I W'Wneds:

Feb. 21, 1939.

M. L. WATERMAN LOOPTAKER FOR SEWING MACHINES Filed Aug. 25, 1937 sshee'ts-sheet 2 (wk. V

wllll III- V Feb. 21, 1939.

M. L. WATERMAN LOOP-TAKER FOR SEWING MACHINES Filed Aug. 25, 1937 3 Sheets-Sheet 3 Patented Feb. 21, 192.9

UNITED STATES PATENT OFFICE 2,148,385 r LOOP-TAKER FOR SEWING MACHINES Max L. Waterman, Fail-field, Conn., assignor to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application August 25', 1937, Serial 20 needle-thread between the lower thread and the lower edge of the needle-aperture in the throatplate during the formation of the stitches.

sewing machine head and bed showing the looptalrer mechanism and the usual reciprocatory 50 needle at substantially the lower end of its stroke. Fig. 2 is a top-plan View showing the gear drive for the loop-taker and a portion of the feeding mechanism.

Fig. 3 represents a substantially central, longitudinal section taken along the line 3 3, Fig. 2. Fig. represents a portion only of Fig. 3, showing the thread-carrier turned clockwise 180 degrees.

Fig. 5 represents a central vertical section of the loop taker body, illustrating the inclined raceway. Fig. 6 represents a vertical section taken along the li '7 is a perspective view of a portion of the cloth-plate with the slide-plate removed, showing the loop-taker in the position in which maximum thread pull-off occurs.

Fig. 8 is an enlarged longitudinal view, partly in section, taken substantially along the centerline of the needle-aperture, showing the slack in the lower thread which facilitates the passage of the needle-thread between the lower thread and the lower edge of the needle-aperture just prior to'the. setting of the stitch by the take-up.

ventlal sewing machine.

Fig. 10 is a disassembled perspective view 01' the loop-taker and thread-carrier, showing the latter removed from the loop-taker.

According to the preferred embodiment of the invention lllustrated, the sewing machine comprises a frame including a bracket-arm head I and bed-plate I' having a reciprocating needle 2,

feed-dog 3, slide-plate 4', and throat-plate 5,

all of common form.

Journaled in a bushing 6 secured in a supporting lug 7 depending from the bed-plate I is an actuating shaft 8 which drives the vertical- 1::

loop-taker shaft 9 is rotated twice for each rotation of the actuating'shaft 8. Y

The loop-taker shaft 9 is preferably journaled in suitable bushings i2 fixed in the vertically spaced horizontally disposed limbs l3, l4 of-the loop-taker supporting bracket i 5. The bushings it are prevented from turning in their respective supporting limbs by the set-screws i6. Disposed between the limbs l3, N of the bracket I5 is the driven spiral gear I I which is fastened securely upon the loop-taker shaft 9 by a set-screw H. The loop-taker supporting bracket I5 is provided at its rearward end with a split bearing-boss id adj ustably clamped upon the bushing 6 by a screw l9.

depending from the bed-plate i. In order to provide for adjustment of the bracket it toward and from the path of needle-reciprocation, the

issued Sept. 28, 1915. Formed integral the loop-taker shaft 23 which is ing the usual in its wall.

erably held in the loop-taker body 23 against displacement by means of an arcuate member or 5 pin 23 and a screw 30.

To insure that the thread-carrier 21' is restrained from rotating with the loop-taker body 23, I have preferably formed in the bottom of the thread-carrier two elongated slots 3|. 32 positioned at diametrically opposite points, (see Fig. 4). As the loop-taker is rotated, each of the slots 3|, 32 engages its respective one of two upstanding detaining teeth 33, 33 formed upon the top 'of, a stationary flat disk 35 disposed within and at the bottom of the cup-shaped body of the loop-taker. Extending downwardly from the bottom of the disk 35 is a rod 36 disposed within the axial bore 31 of the loop-taker shaft 9. As clearly illustrated in Fig. 3, the lower end of the rod 36 extends below the lower end of the shaft 3 and is clamped against rotation preferably by the split bushing 38 supported in the split lower end 39 of the L-shaped bracket 40 which is rigidly secured to the loop-taker supporting bracket I! by the screw 4|. The clamping screw 42 maintains the split bushing 38 in tight gripping engagement with the lower end of the rod 36.

It will be seen by reference to Figs. 3 and 4 that as the loop-taker is rotated the inclination of the raceway 25 causes the non-rotating thread-carrier 21 to progressively tilt in all directions with respect to the axis of movement of the looptaker. tion of the thread-carrier will be referred to as a wabbly" motion. The wabbly motion of the thread-carrier effects an alternate engagement and disengagement of the walls of the elongated slots 3|, 32 in the thread-carrier 21 with thedetaining teeth 33, 33 on the disk 35. It will be understood that when one ofthe detaining teeth is temporarily disengaged, the needle-thread loop can unrestrictedly pass between the bottom of the thread-carrier 21 and the top of the disengaged detaining tooth while the second detaining tooth prevents the thread-carrier from rotating. Upon further turning of the loop-taker, the second detaining tooth is disengaged from the threadcarrier after the first detaining tooth engages it. This alternate engagement and. disengagement of the thread-carrier slots with the detaining Y teeth is so timed that the needle-thread loops during each 'path of needle-reciprocation.

may be cast unobstructedly around the threadcarrier. The detaining teeth 33, 34 are of sumcient height so that the thread-carrier during its wabbly movement is at no time free to rotate with the loop-taker.

It has been found that due to the wabbly motion imparted to the thread-carrier a definite pull-off action on the lower thread occurs once stitch-forming cycle. This pull-ofi action occurs during the time in which the thread-carrier is moving bodily away from the Maximum pulloff action occurs when the loop-taker and threadcarrier are inthe position illustrated in Fig. 7. In addition to. the the lower thread, the wabbly motion of the thread-carrier also produces slack in the lower thread, as shown in Fig. 8. This slack in the lower thread is produced after the pull-off action occurs and during the time the thread-carrier moves bodily toward the path of needle-reciprocation. As clearly shown in Fig. 8, this desirable slack in the lower thread T' readily permits the loop of the needle-thread T" to pass between the lower thread T and the edge 43 of the needleaperture 44 in the throat-plate 5. In Fig. 9 it can be seen that, in'the conventional sewing ma- Hereinafter this progressively tilting mo-.

therein, said raceway portion,

way, and means for restraining said thread-car- 4 desirable pull-off action on chine, the lower thread "I" is taut and in order for the loop of the needle-thread T" to pass by the edge 43 it is necessary for the take-rup to exert a considerable tension on the thread T".

By reference to Fig. 6,it will be observed that the side-walls of the slots 3|, 32 formed in the bottom of the thread-carrier 21 are upwardly flared, and the effective side-walls of the detaining teeth 33, 33 are flat and disposed at right angles to the top surface of the disk 35. Obviously, the side-walls of the detaining teeth may be downwardly flared and the side-walls of the slots in the thread-carrier may be vertical without in any way affecting the operation of the mechanism. It has been found that by suitably shaping the'slots and the detaining teeth a minimum amount of play is afforded between the two,thereby resulting in a very quiet operation of the mechanism at comparatively high speeds.

From the foregoing description, it is obvious that the present invention contemplates an improved rotation-restraining means for the threadcarrier of a loop-taker, and by properly shaping the slots in the thread-carrier'a'nd the surfaces of the detaining teeth a mechanism is produced which functions efliciently and with a minimum amountof noise.

The invention is not to be understood as limited to the details of construction and arrangement of parts shown and described as a preferred embodiment of the invention, as various, be made by those modifications may obviously skilled in the art within the spirit and scope of the invention.

Having thus set forth the nature of the invention what I claim herein is:-

1. A loop-taker for sewing machines comprising a body-portion having an axis of rotation, a

thread-carrier journaled in said body-portion,

the bearing between the two being disposed in a plane inclined to the axis of rotation of said loop-taker whereby to cause the thread-carrier to move with a wabbly motion when the looptaker is actuated, and means for restraining said thread-carrier against turning movement with the loop-taker.

2. A loop-taker ing a body-portion for sewing machines comprishavinga raceway formed being disposed in a plane inclined to the axis of movement of said bodya thread-carrier journaled in said racerier against turning movement with the loop-' taker.

3. A loop-taker for sewing machines comprising a body-portion having a raceway formed therein, said raceway being disposed in a plane inclinedto the axis of movement of said body-portion, a. thread-carrier journaled in said raceway, and a plurality of detent means alternately engaged by said thread-carrier for restraining it against turning movement.

4. A loop-taker for sewing machines comprising a body-portion having a raceway formed therein, said raceway being disposed in a plane inclined to the axis of movement of said body-portion, a thread-carrier journaled in said raceway, and a plurality of means for restraining said threadcarrier against turning movement with the looptaker, said means being rendered effective by the turning movement of said loop-taker to alternately engage said thread-carrier.

5. A loop-taker for sewing machines comprls formed in journaled in said therein a plurality raceway and having formed of slots, and detent means alsaid thread-carrier with the loop-taker.

6. In a sewing machine, a loop-taker comprising a body-portion having an inclined raceway said body-portion, a thread-carrier against engaged by said slots for restraining the threadcarrier against turning movement.

7. In a sewing machine, a loop-taker having a body-portion formed with an inclined raceway, a thread-carrier journaled in said raceway and having formed therein a plurality of slots, a shaft having an axial bore supporting said loop-taker. a stationary rod disposed w'ithin the axial bore of said shaft and terminating in a disk, and a plurality of teeth formed on said disk,said teeth arranged to be alternately engaged by the slots in the thread-carrier for restraining the latter against turning movement. i 8. In a sewing machine, a reciprocatory'needle, a loop'staker cooperating with said needle in the formation of stitches. a thread-carrier so Journaied in said loop-taker as to have a wabbly motlon as the loop-taker is actuated, and stationary means for restraining the thread-carrier against turning movement.

9. The combination with a reciprocatory needle and a throat-plate having a needle-aperture, of a circularly moving loop-taker, a thread-carrier for the lower threadconcentrically located in said means for restraining the thread-car- 10. A sewing machine having,

MAX L. WATERMAN. 

